- Introduced ELPA_ONE_STAGE (see #4683).
- QR factorization (unsafe is now internal).
- Removed keyword ELPA_QR_UNSAFE.
- Updated to ELPA 2025.06.002.
- Disabled IEEE exceptions.
- Test coverage.
- For the OpenCL based GPU code-path, or by choice, ELPA may not be built with GPU support.
- Introduced __NO_OFFLOAD_ELPA to allow CPU-only ELPA (related to #4617).
- Allow compile-time selection of ELPA solver-kind (1-stage vs 2-stage).
- For ELPA/SYCL, use 1-stage ELPA solver by default for the time being.
- ELPA/SYCL (MKL in general?) has an index-fix currently only in a branch.
Index/ILP issue (undefined behavior):
- ELPA eventually mismatches index-kinds (LP64 vs ILP64 when linking BLAS/MKL).
- For static linkage it usually does not not matter (at least CPU-only).
- CP2K links the correct BLAS flavor (SO and GPU-build may be affected?).
- ELPA 2-stage may be even affected beyond MKL (or for GPU in general).
- ELPA 1-stage is apparently not affected by index issue.
- Introduced offload_mempool_stats_print to Fortran API.
- Print memory statistics independent of DBM (and grid).
- Avoid circular dependency (string_utilities/strlcpy_c2f).
- Use up-leveled MPI/C wrapper.
* MPI/C wrapper (dbm_mpi_ to cp_mpi_)
- Adjusted license of C-MPI wrapper (consequence of mpiwrap).
- Moved wrapper for C languages in to mpiwrap directory.
- Avoid name clash (same basename as for Fortran).
- Renamed prefix of all MPI wrapper functions.
* Other (DBM):
- Improved handling errors (OFFLOAD_CHECK before launch).
- Permit/Adjusted preprocessor symbol (precommit hook).
- Avoid multi-line control-flow w/o curly braces.
- Double-check #4428 (DBM_MULTIPLY_COMM_MEMPOOL).
* TODO
- Apply offload/print_func pattern to GRID's print_func.
- Leverage offload_mempool for grid backend.
- Split backend_upload_packs into two phases on GPU.
- Initial phase is chosen to have not triggered upload.
- Offload: offloadEventQuery to check if GPU is busy.
- Removed dbm_multiply_gpu_download_results
- Transfers are launched as early as possible.
- Improved overlap between transfer/compute.
- Idea: proceed on CPU if GPU is busy.
Other changes:
- Documented way to perform validation (ctx=NULL).
- Permit DBM_ prefix for preprocessor symbols.
- Removed C-shard pointer from GPU-context.
- Per-shard event stored/provided by shard.
- Migrated CPU-options into context.
- Miniapp: allow to omit validation.
- Use preincrement (atomic).
- Experimented with specialized vs DBM's universal kernel.
- Performance is equal likey due to data mix/sort (TODO).
- DBCSR/unrelated: Likely introduce DBM-kernel (cleaner).
- Rely on OPENCL_LIBSMM_PFORMAT.
Mempool:
- Revised default to skip mempool for host-allocs if offload
is not compiled-in or if offload-allocs on host are disabled.
- Renamed and split DBM_ALLOCATION_FACTOR.
- Separate DBM_OVERCOMMIT_DEVICE/HOST.
- More rigid control of mempool config
- Conditionally define mempool lists.
Other:
- Passing batch/task data in const-correct fashion.
- Revised verbose output.
- Apparently, MPI_Alloc_mem/free are not fully thread-safe.
- Debug shows issue similar to issues reported elsewhere.
- Note: MPI_Alloc_mem was taken out of critical section.
